Electrically Insulative and Thermally Conductive Parallel Battery Cooling and Temperature Control System

ABSTRACT

A battery is provided having heat transfer bars that directly transfer heat between the interior layers of a battery cell and the case that encloses the battery cell. The battery does not transfer significant heat from its interior layers to the posts of the battery that reside outside of the battery case. A temperature-controlled power system also is provided that uses multiple, active thermoelectric devices paired with multiple batteries to provide individual temperature control of the individual batteries forming the power system. The multiple, active thermoelectric devices preferably transfer heat to a single radiator on each side of the power system. A method of transferring heat from a battery interior using conductive, active, and convective heat transfer is also described.

REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. Nonprovisional application Ser.No. 16/835,816, filed Mar. 31, 2020, entitled “Electrically Insulativeand Thermally Conductive Parallel Battery Cooling and TemperatureControl System”, which claims the benefit of U.S. ProvisionalApplication No. 62/827,799 entitled “System and Method for BatteryThermal Management” filed Apr. 1, 2019, both of which are incorporatedby reference in the entirety.

BACKGROUND

Lithium ion and similar battery types generate significant heat duringcharging and discharging, especially with rapid charging or dischargingas common in automotive power applications. To manage heat removal inthe automotive battery context, air and liquid flows have been used toremove heat from the batteries. Conduction of heat from the batteriesinto thermoelectric materials that then actively transfer the heat toair or fluid flows also have been used to remove heat from thebatteries.

Cells for automotive use batteries may be built up by rolling acontinuous sheet having a cathode layer, an electrically insulativeseparator layer, and an anode layer sandwiched between electricallyinsulating polymeric exterior layers. By rolling the continuousmulti-layer sheet around an interior frame that is then removed to leavea central void, multiple layers of the polymeric exterior are incontact, resulting in a “jelly roll” battery cell. The bare,electrically conductive anode and cathode layers protrude at oppositeends of the jelly roll, as the opposing ends of the continuous sheetlack the electrically insulative polymeric exterior layers. Folding thepolymeric exterior continuous sheet at fixed intervals back onto itselfin a Z-pattern can provide a similar battery cell in the form of a flatstack as opposed to a roll—similarly to Post-It™ notes. Thus, the cellof the resulting battery can have a central void if formed as a roll, orcan be formed as a solid stack if folded onto itself.

A cooling method relying on heat transfer through the contactingelectrically insulative polymeric exterior layers of the sheet of theroll or stack has the issue that the only way that heat from theinterior layers of the cell can reach the exterior of the cell is bypassing through multiple layers of polymeric material, which in additionto being an electrical insulator, is a thermal insulator. This type ofheat transfer may be thought of as serial heat transfer as heat mustpass from an interior layer through additional interior layers to reachan exterior layer, so the heat can be removed from the outermostpolymeric exterior layer by the cooling system. Thus, the flat stack cantransfer heat from the bottom and top flat, exterior surfaces and a rollcan transfer heat to the exterior surfaces outside and inside the roll,but there is no way with either construction to directly transfer heatfrom the interior layers for the roll or stack without the heat firsthaving to transfer through additional interior layers to reach anexterior layer.

The only way to directly transfer heat from the interior layers of thecell is through the cathode and anode layers residing in each layer ofthe rolled or folded sheet. As the cathode and anode materials are oftenelectrically conductive metals, with aluminum forming the cathode (wherereduction occurs) and copper forming the anode (where oxidation occurs)for example, a direct heat transfer pathway exists from the interiorlayers of the cell out through the cathode and anode layers, which arenot covered by the polymeric material. Transferring heat from theseprotruding electrically and thermally conductive surfaces may bereferred to as parallel heat transfer as heat is being transferreddirectly from multiple interior layers simultaneously to the exteriorsurfaces that form the cathode and anode.

An issue with conventional parallel heat transfer techniques, whichtransfer heat from the interior cathode and anode layers of the cell, isthat when the cell is turned into a battery the cathode and anode layersare electrically and thermally connected to relatively small surfacearea electrodes or “posts”. Thus, the interior cell heat transfers fromthe relatively large surface areas of the cathode and anode of the cellto the smaller surface area posts residing external to the cell of thebattery. In this way the exposed posts of the battery serve as “coldfingers” in relation to the interior layers of the battery cell.Conventionally, bus bars and other thermally conductive components arethen attached to the battery posts residing external to the battery,which provide the surface area from which the heat is removed. However,the contact area establishing electrical conductivity between thebattery posts and the cathode and anode of the cell limits the rate atwhich heat may be transferred from the interior layers of the battery tothe bus bars and/or other thermally conductive components residingexternal to the battery.

Conventional parallel heat removal techniques also exist where athermally conductive tube is clamped to the cathode and/or anode of thecell where an aqueous liquid is passed through the tube to remove theheat from the cathode and/or anode. This design does not limit heattransfer from the interior layers of the battery with the connectionbetween the cathode and anode electrode posts being a choke point as thepreviously discussed “post only” conventional designs. However, these“internal liquid” designs suffer from being difficult to manufacture asthe tube must be made from a thermally but not electrically conductivematerial to prevent shorting between the cathode and/or anode and thecirculating liquid. Furthermore, especially in automotive applications,as the liquid is in close proximity to the battery cell, such designshave a high probability of the aqueous liquid coming in contact with thecathode, anode, and/or cell materials and causing extreme heating andfire if the battery is damaged in an accident.

As can be seen from the above description, there is an ongoing need forsimple and efficient designs and materials to cool batteries duringcharging and discharging, especially in the context of lithium ionbatteries used in automotive power applications. The designs, devices,and materials of present invention overcome at least one of thedisadvantages associated with conventional devices.

SUMMARY

The present design provides a battery with or without active coolingprovided by thermoelectric devices and/or a heat transfer fluid thatmakes possible high battery charge and discharge rates, thus extremefast charging and discharging, without overheating the cell of thebattery. The design enables longer and thicker cells to be used inconstructing the battery, significantly improved cell life, and ease ofmanufacture and assembly.

The present design of a temperature-controlled power system providesmany benefits, including nearly silent operation, high capacity coolingand heating in one unit, lower parasitic heat loads in relation toconventional systems, reduced temperature gradients between batteries,and the ability to simultaneously heat and cool different batteries.

In one aspect, the invention provides a battery including a parallelheat transfer system, where the battery includes a case comprising a canattached to a lid; a cell having first and second electrodes exposedfrom an exterior layer of polymeric material of the cell, the at leasttwo electrodes comprising an anode electrode and a cathode electrode,where the case encloses the cell; at least two posts exposed from thecase; at least two contacts enclosed by the case, where a first of theat least two posts is in electrical communication with a first of the atleast two contacts and a second of the at least two posts is inelectrical communication with a second of the at least two contacts; andat least a first heat transfer bar in electrical and thermalcommunication with the first electrode and the first of the at least twocontacts, where the first heat transfer bar comprises a first side thatis thermally and electrically conductive and a second side that isthermally but not electrically conductive. The battery may include asecond heat transfer bar configured similarly to the first.

In another aspect of the invention, there is a temperature-controlledpower system, the temperature-controlled power system includesbatteries; and a thermal transfer system, where the thermal transfersystem includes at least one circuit board; control circuitry inelectrical or wireless communication with the at least one circuitboard; at least two active thermoelectric devices held by the at leastone circuit board, where each of the at least two active thermoelectricdevices contacts and is in thermal communication with a differentbattery; and at least one radiator in conductive heat transfer with theat least two active thermoelectric devices. The power system may includeadditional active thermoelectric devices in a second circuit board thatcontact a second radiator on the opposite side of the batteries.

In another aspect of the invention, method of transferring heat from abattery cell to surrounding air includes generating heat from theinterior layers of a cell by flowing current into or out of the cell;conductively transferring the heat from cathode and anode layers of theinterior layers of the cell to an exterior cathode electrode of the celland to an exterior anode electrode of the cell; conductivelytransferring the heat from at least one of the electrodes to a heattransfer bar contacting the at least one of the electrodes; conductivelytransferring the heat from the heat transfer bar through a thermallyconductive and electrically insulative material into an interfacing faceof the heat transfer bar; conductively transferring the heat from theinterfacing face into a can of the battery; conductively transferringthe heat from the can of the battery to a cold side of an activethermoelectric device, where the active thermoelectric device transfersthe heat from the cold side to a hot side; conductively transferring theheat from the hot side of the thermoelectric device to a radiator, wherethe radiator convectively transfers the heat to surrounding air. Theradiator may conductively transfer the heat to a heat transfer fluidthat convectively transfers the heat to the surrounding air after theheat transfer fluid leaves the radiator.

Other systems, methods, features and advantages of the invention willbe, or will become, apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features, andadvantages be included within this description, be within the scope ofthe invention, and be protected by the claims that follow. The scope ofthe present invention is defined solely by the appended claims and isnot affected by the statements within this summary.

BRIEF DESCRIPTION OF THE FIGURES

The invention can be better understood with reference to the followingdrawings and description. The components in the figures are notnecessarily to scale, emphasis instead being placed upon illustratingthe principles of the invention.

FIG. 1 represents a battery cell and a pair of heat transfer bars.

FIG. 2 represents a battery including a case that encloses a cell inthermal and electrical communication with heat transfer bars.

FIG. 3 represents a temperature-controlled power system including athermal transfer system and multiple assembled batteries.

FIG. 4A represents a close-up and thus more detailed view of thetemperature-controlled power system as previously represented in FIG. 3.

FIG. 4B represents a close-up and thus more detailed view of the TEDsheld in the circuit board by the slots.

FIG. 4C represents an additional circuit board design where two TEDsreside on the same side at each battery position.

FIG. 5A represents one implementation of a radiator showing a cut-awayof the interior.

FIG. 5B provides a representation of a compression plate includingholes.

DETAILED DESCRIPTION

A battery is provided having heat transfer bars that directly transferheat between the interior layers of a battery cell and the caseenclosing the battery cell. The battery does not transfer significantheat from its interior layers to the posts of the battery that resideoutside of the battery case. A temperature-controlled power system alsois provided that uses multiple, active thermoelectric devices pairedwith multiple batteries to provide individual temperature control of theindividual batteries forming the power system. The multiple, activethermoelectric devices preferably transfer heat to a radiator on eachside of the power system. While the application is written mostly in thecontext of cooling a battery or batteries, the battery or batteriescould likewise be heated by supplying heat to the thermal transfersystem from an exterior source.

FIG. 1 represents a battery cell 105 and a pair of heat transfer bars150. The cell 105 includes an exterior layer 110 of the polymericmaterial that forms the outside layers of the continuous sheet that alsoforms interior layers 120 of the cell 105. The polymeric materialforming the exterior layer 110 is electrically insulative and arelatively poor thermal conductor. The cell 105 includes electrodes 130formed from the anode and cathode layers that are continuous through thesheet and are separated by an electrically insulating spacer layer thatalso is continuous through the sheet. The electrodes 130 are made froman electrically and thermally conductive material, preferably aconductive metal such as copper, aluminum, and the like. The electrodes130 extend outside of the exterior layer 110 of the polymeric material.

The heat transfer bars 150 are formed from an electrically and thermallyconductive material, preferably a conductive metal such as copper,aluminum, steel, iron, and the like. Preferably, the heat transfer bars150 are solid conductive metal. The heat transfer bars 150 hold throughcontact, such as ultrasonic welding or interference fit, with theelectrodes 130. The heat transfer bars 150 may be force fit to theelectrodes 130, may be heated and contacted with the electrodes toachieve an interference fit upon cooling to the temperature of theelectrodes 130, or may be welded together, such as ultrasonically, andthe like. While two heat transfer bars 150 are represented, one may beused on either of the two electrodes 130.

The heat transfer bars 150 are in close or direct contact with theelectrodes 130 and thus preferably do not include a space where a liquidcan readily flow between the electrodes 130 and the heat transfer bars150. Thus, the heat transfer bars 150 preferably lack interior passagescapable of transporting a liquid.

The heat transfer bars 150 contact at least 60% of a longitudinal lengthof the electrodes 130, preferably at least 80% of the longitudinallength of the electrodes 130. Preferably the heat transfer bars 150 arein contact with at least 70% of a lateral width of the exposedelectrodes 130, more preferably at least 90% of a lateral width of theexposed electrodes 130. While the cell 105 is represented withrectangular shaped electrodes and thus corresponding rectangular shapedchannels in the heat transfer bars 150, other geometric shapes may beused for the electrodes 130 and the heat transfer bars 150 that providethe desired contact between the two. For example, cross-sectionallycircular or dove-tail shaped electrodes would have circularcross-section or dove-tail shaped heat transfer bars respectively, asshown in the figure inset.

The heat transfer bars 150 have a surface opposite where the electrodes130 clamp that is coated with a thermally conductive and electricallyinsulative material. Thus, the heat transfer bars 150 have a first orinner side that is a thermally and electrically conductive side 170contacting the electrode 130 and a second or outer side that is athermally but not electrically conductive side 180 contacting aninterior side of the battery case (not shown). The outer side 180preferably includes a geometric pattern that forms an interfacing face185.

The thermally conductive but electrically insulative material of theouter side 180 of the heat transfer bars 150 is preferably a dielectricmaterial, such as anodizing, a non-electrically conductive paint, or aplasma electrolytic oxidation (PEO) coating, Preferably, the thermallyconductive but electrically insulative material is a PEO material, suchas available from Keronite, Greenwood IN or from IBC Group, Lebanon INunder the tradename Ceratough™.

FIG. 2 represents a battery 200 including a case 290 that encloses acell 205 in thermal and electrical communication with heat transfer bars250. The battery 200 may be used individually or multiples of thebattery 200 may be electrically combined to provide increased voltageand/or amperage. The case 290 includes a can 292 and a lid 295, wherethe lid 295 forms a seal (not shown) with the can 292. The case 290 ismade from a thermally conductive material that may or may not beelectrically conductive. Preferably, the case 290 is made from a metal,such as aluminum, steel, copper, magnesium, or the like. Preferably theseal between the can 292 and the lid 295 substantially excludes moisturefrom the cell 205, and more preferably substantially excludes moistureand air from the cell 205. The seal may be provided through laserwelding, by metal edges that do or do not distort on compression, agasket, an adhesive, combinations thereof, and the like and may or maynot provide thermal conduction between the can 292 and the lid 295.Preferably, the seal is formed from laser welding the can 292 to the lid295.

The can 292 provides the primary path for heat transfer, whether throughconvection or conduction, from the cell 205 and thus the battery 200.Substantially all the heat drawn from the interior layers of the cell205 is passively transferred to the exterior surfaces of the can 292.Furthermore, at least 70% of the heat drawn from the cell 205 ispassively transferred to exterior surfaces of the can 292, preferably atleast 90% of the heat drawn from the cell 205 is passively transferredto the exterior surfaces of the can 292. While not shown in the figure,the case 290 may include one or more temperature sensors that sense thetemperature of the can 292 and/or case 290, the cell 205, the electrodes230, and/or heat transfer bars 250.

The can 292 preferably includes a receiving geometric pattern 287 onopposing interior sides that receives interfacing face 285 of the heattransfer bars 250. In this context “interfacing” preferably means thatonce joined, the heat transfer bars 250 and the receiving geometricpattern 287 on the interior of the can 292 limit movement of the heattransfer bars 250 in at least one dimension. While the figure representsthe battery 200 as having two of the heat transfer bars 250 on oppositesides of the cell 205 and two of the receiving geometric patterns 287 onthe opposite interior sides of the can 292, if less cooling is desiredfor the cell 205, a single heat transfer bar may be interfaced with asingle receiving geometric pattern on the interior of the can 292.

The interfacing face 285 preferably contacts at least 60% of an interiorlength of the can 292, thus the can 292 preferably includes thereceiving geometric pattern 287 along at least 60% of an interiorlength. The interior length may be a shorter or longer interior side ofthe can 292. More preferably, the interfacing face 285 contacts at least80% of the interior length of the can 292, with the can 292 includingthe receiving geometric pattern 287 along at least 80% of the interiorlength. The contact between the electrodes 230 and the heat transferbars 250 provides a primary thermal transfer path from the cell 205 tothe exterior surfaces of the case 290 through conduction. With regard tothe interfacing face 285, contact includes the circumstances wheredielectric grease and other such materials are used to provide orenhance the contact, thus enhancing thermal conductivity in relation tohaving thermal insulation arising from an air-gap, and excludecontaminants.

In addition to the receiving geometric pattern 287, the can 292preferably also includes one or more interior surfaces making contactwith exterior layer 210 of the cell 205. More preferably, the can 292includes two opposing interior surfaces making contact with the exteriorlayer 210 of the cell 205. The contact between the interior surface ofthe can 292 and the exterior layer 210 of the cell 205 provides asecondary thermal transfer path from the cell 205 to the exteriorsurfaces of the case 290 through conduction. However, as the primarythermal transfer path is from the electrodes 230 through the heattransfer bars 250 and into the case 290, the secondary thermal transferbetween the exterior layer 210 and the case 290 may serve to heat theexterior layer 210, thus providing the benefit of a reduced temperaturegradient across the exterior and interior layers of the cell 205.Additionally, if the can 292 is thermally insulated from the lid 295 bythe seal, the temperature of the can 292 will be significantly higherthan the temperature of the lid 295, as the lid 295 is thermallyinsulated from the can 292, which receives primary heat transfer fromthe heat transfer bars 250 and secondary heat transfer from the exteriorlayer 210.

The lid 295 includes electrode contacts 240 that establish electricalcommunication between electrodes 230 and battery posts 245. The contacts240 reside in the interior of the case 290, while the posts 245 extendto the exterior of the case 290 to provide electricity to the load. Theposts 245 are electrically insulated from the lid 295. While the lid 295is preferably made from the same thermally conductive material as thecan 292 for ease of manufacture, as the lid 295 may be formed from arelatively poor thermally conductive material in relation to the can292. The lid 295 may be made from a polymeric and/or composite materialthat is thermally and/or electrically insulative. Thus, while preferablethat the exterior surfaces of the case 290 are efficient thermaltransmitters, thermal transfer from the cell 205 may be substantiallylimited to the can 292.

The contacts 240 are made from an electrically conductive material thatalso may be thermally conductive, such as copper, aluminum, steel,magnesium, and the like; however, the contacts 240 do not have to bethermally conductive. The posts 245 are made from an electricallyconductive material that also may be thermally conductive, such ascopper, lead, aluminum, and the like; however, the posts 245 do not haveto be a good thermal conductor. Thus, unlike the can 292, the posts 245do not have to be thermally conductive.

The contacts 240 engage with electrically and thermally conductive side270 of the heat transfer bars 250 to establish electrical communicationbetween the electrodes 230 and the posts 245, thus providing electricalcommunication between the “inside” and the “outside” of the battery 200.This engagement may be purely mechanical, such as when spring forceholds the contacts 240 against the thermally conductive side 270 of theheat transfer bars 250 after the contacts 240 are forced onto the heattransfer bars 250. Engagement between the contacts 240 and the thermallyconductive side 270 of the heat transfer bars 250 also may be permanent,such as when the contacts 240 and the thermally conductive side 270 ofthe heat transfer bars 250 are welded together. Ultrasonic welding ispreferred.

Unlike the heat transfer bars 250 that engage at least 60% of thelongitudinal length of the electrodes 230 to provide primary thermaltransfer from the cell 205, the contacts 240 can engage a relativelysmall surface area of the conductive side 270 of the heat transfer bars250 as efficient electrical communication and not thermal communicationwith the electrodes 230 is required. Preferably the relatively smallsurface area of the conductive side 270 of the heat transfer bars 250,is less than 30% of the longitudinal length of the first side of theheat transfer bars 250.

The posts 245 may provide a relatively minor third path of thermaltransfer from the cell 205, but as the posts 245 are electricallyinsulated from the lid 295, and likewise substantially thermallyinsulated from the lid 295, heat does not effectively conductivelytransfer from the contacts 240 to the exterior surfaces of the case 290.This is very different that conventional designs requiring significantcontact between the posts and the electrodes for cooling when bothelectrical and primary heat transfer from the cell is shared through theposts.

FIG. 3 represents a temperature-controlled power system 302 including athermal transfer system 301 and multiple assembled batteries 300. Thethermal transfer system 301 includes at least one radiator 320, andpreferably includes at least one circuit board 358 and at least twoactive thermoelectric devices 352.

The batteries 300 of the temperature-controlled power system 302 may beconductively cooled by active thermoelectric devices 352 that areconvectively cooled by the surrounding air. The batteries 300 may beconductively cooled by the one or more radiator 320 that transfers heatto the surrounding air and/or into a heat transfer fluid (not shown).The batteries 300 may be conductively cooled by active thermoelectricdevices 352 that are conductively cooled by one or more radiator 320that convectively transfers heat to the surrounding air or preferablytransfers heat into a heat transfer fluid.

The heat originating from the multiple batteries 300 may be directlyconvectively transferred to the surrounding air, or conductivelytransferred to active thermoelectric devices that are then directlyconvectively cooled by the surrounding air. However, in either instance,the “surrounding air” may be replaced by one or more radiators 320 thatadsorb the heat for transfer into the surrounding air and/or into a heattransfer fluid passing through the one or more of the radiators 320.

The temperature-controlled power system 302 includes battery carrier 304that carries the batteries 300, optional circuit board 358 and TEDs 352,and optional radiator 320. As previously discussed, when the batteriesare directly cooled by convection, the circuit board 358, TEDs 352, andradiator 320 are omitted. When the radiator 320 is in the form of aconvective heat sink that conductively adsorbs heat from the batteries300 and convectively radiates the heat to the surrounding air, thecircuit board 358 and TEDs 352 may be omitted. When the TED's directlyradiate heat to the surrounding air convectively, the radiator 320 maybe omitted. Preferably, the temperature-controlled power system 302includes the circuit board 358, the TEDs 352, and the radiator 320, thushaving ability to conductively transfer heat from the batteries to theTEDs and then conductively transfer heat from the TEDs to the radiator,where the radiator transfers the adsorbed heat to a circulating heattransfer fluid—thus permitting the heat to be convectively lost at alocation distanced from the temperature-controlled power system 302.

The battery carrier 304 preferably provides a base 303 on which thebatteries 300 reside. The battery carrier 304 also preferably providesone or more divider and ends 306, 308 that separate the batteries 300and that retain the vertical positioning of the batteries 300,respectively. While not shown in the image, the battery carrier 304 mayomit the dividers 306 when thermal conductivity between the batteries300 is desired. When the battery carrier 304 includes the dividers 306,the thermal insulation between the batteries 300 provided by thedividers 306 permits thermal control of each of the batteries 300individually when individual active thermoelectric devices are used forcooling of the batteries 300. Thus, it is possible to heat a firstsubset of the batteries 300 while simultaneously cooling a second subsetof the batteries 300. The ability to monitor and control the temperatureof the batteries 300 individually is advantageous when multiple of thebatteries 300 are electrically connected in series to increase voltageover that of a single battery or are electrically connected in parallelto increase current over that of a single battery. In either instancethe batteries 300 on the “ends” of the battery carrier 304 have atendency to heat at a slower rate than the batteries 300 at the “middle”of the battery carrier 304. Thus, individual battery temperaturemonitoring and control advantageously provides the benefit of a reducedtemperature gradient across the batteries 300 when at least three of thebatteries 300 are present.

The battery carrier 304 is preferably made from an electricallyinsulating and thermally insulative material, preferably a polymercomposite, such as glass filled nylon, polypropylene, ABS, and the like.While a single material is represented in the figure, multipleinsulative materials may be used to form the battery carrier 304. Thebattery carrier 304 may be formed from a single or from multiple parts,for example, when the divider and ends 306, 308 are separate parts thatare attached to the base 303 of the battery carrier 304. The batterycarrier 304 may include mounting points such as studs (not shown) and/orthreaded inserts 325.

The circuit board 358 holds the active thermoelectric devices (TEDs)352. The TEDs 352 have slots 353 on opposing longitudinal sides thatpermit the TEDs to slide into the circuit board 358 and be movementconstrained in the dimensions perpendicular to the circuit board 358.The circuit board 358 includes cut-outs 355 to receive and hold the TEDs352 and to prevent substantial side to side movement of the TEDs 352 inthe plane of the circuit board 358. Thus, the TEDs 352 can move up anddown in the plane of the circuit board 358, but the slots 353 preventperpendicular movement in and out of the plane of the circuit board 358.The circuit board 358 preferably includes holes 322 that may be used toaffix the circuit board 358 including the TEDs 352 to the batterycarrier 304, thus creating contact between the TEDs 352 and thebatteries 300.

The TEDs 352 slide into the cut-outs 355 of the circuit board 358 untilelectrical contacts 354 electrically and mechanically engage withcircuit board connectors 356. Once the contacts 354 engage theconnectors 356 through interference fit, the TEDs 352 can no longerfreely move up and down in the plane of the circuit board 358. Thesizing of the openings in the circuit board 358 correspond with theslots 353 in the TEDs 352. The sizing of the TEDs 352 preferablycorresponds to the width and height of the exposed sides of thebatteries 300. Thus, the TEDs 352 directly contact and conductivelytransfer heat from the individual cases of the batteries 300, preferablywith an individual TED 352 or two for each battery 300, thus allowingindividual batteries 300 to be heated or cooled.

The TEDs 352 do not directly contact or transfer heat from the batteryposts 345 or associated bus bars and related structures (not shown) thatmay be used to carry the primary current to and from the batteries 300.Thus, the hot and cold sides of the TEDs 352 are not in contact with theprimary current carrying components of the system, which facilitatesmanufacturing.

Preferably, at least 30% of the area of the side of each batterycontacts and is thus in conductive thermal communication with a side ofthe corresponding TED 352, more preferably at least 60% of the area ofthe side of each battery is in contact and thus conductive thermalcommunication with a side of the corresponding TED 352. When thetemperature-controlled power system 302 includes TEDs 352 on oppositesides of the batteries 300, as represented in the figure, each of thebatteries 300 is in contact with two TEDs 352, one contacting each ofthe two opposing sides not contacting the battery carrier 304.Preferably, the TEDs 352 are not in contact with the top of thebatteries 300, thus not in contact with the battery lids.

The radiator 320 may not include a heat transfer fluid, thus being aheatsink that directly transfers heat to the surrounding air throughfins and the like. Preferably, the radiator 320 includes a heat transferfluid which circulates through internal passageways in the radiator 320to transfer heat from the TEDs 352 to the heat transfer fluid.

While one side of the temperature-controlled power system 302 isrepresented as a cut-away in this figure, thus showing one outer partialside of the batteries 300, a partial outer face of a first circuitboard, a partial inner face of a second circuit board that is notobscured by the batteries 300, and a portion of a single radiatoropposite the cut-away side not obscured by the circuit board, thetemperature-controlled power system 302 may be similarly configured witha circuit board, TEDs, and radiator on one or more sides, preferably thetwo opposing longitudinal sides as represented in the figure.

FIG. 4A represents a close-up and thus more detailed view of thetemperature-controlled power system as previously represented in FIG. 3. Opposing, longitudinal slots 453 of the TEDs 452 are seen holdingopposing longitudinal sides of the TEDs 452 in the plane of circuitboard 458. The figure also represents that the width of the TED 452approximately corresponds to the width of the battery 400, as ispreferred. The TED 452 has a cold side in contact with the side of thebattery 400, and a hot side in contact with radiator 420 when activelycooling the battery 400.

FIG. 4B represents a close-up and thus more detailed view of the TEDs452 held in the circuit board 458 by the slots 453. Control circuitry459 including at least one processor and memory storage is alsorepresented on the circuit board 458 that can monitor temperaturesensors (not shown), which may be placed inside or outside the case ofthe battery 400 to adjust the voltage and/or polarity of the potentialapplied to the TEDs 452 in response to temperature readings obtainedfrom the sensors. The control circuitry 459 also may monitor temperaturesensors (not shown) incorporated with the radiator 420 or a heattransfer fluid to further alter the voltage and/or polarity of thepotential applied to the TEDs 452. By reversing the polarity between afirst and a second opposite polarity input to the TEDs, the system canswitch between cooling or heating the batteries 400, respectively.

The temperature sensors may be thermocouples or like physical devices,or other parameters of the batteries may be monitored, and theseparameters turned into temperature readings of the batteries via analgorithm. Additionally, the side of one or more of the TEDs 452contacting a battery may be used as a temperature sensor by measuringthe Seebeck voltage across the TED. Other methods of obtainingtemperature information may be used. While the figure represents thecontrol circuitry 459 being incorporated into the circuit board 458, thecontrol circuitry 459 may be remotely located and in electrical orwireless communication with the circuit board 458.

In view of the available temperature information, battery load, and thelike, the control circuitry 459 also may alter the rate of heat transferfluid flow through the radiator 420 by adjusting the operation of acirculating pump or similar fluid flow device (not shown). The controlcircuitry 459 preferably includes the ability to independently adjustthe TED 452 or pair of TEDs 452 that cool or heat a single battery 400.In addition to adjusting the input to the TEDs 452 in response to thetemperature sensors, the control circuitry 459 also may adjust thecurrent outflow or inflow to individual batteries 400 or to all thebatteries 400 to prevent damage to the batteries 400 under extreme loador charging conditions. Thus, the control circuitry 459 also may managecharging and/or discharging of the batteries 400 to optimize performanceand/or longevity of the batteries 400.

FIG. 4C represents an additional circuit board 458 design where two TEDs452 reside on the same side at each battery location. As with thecircuit board 458 design of FIG. 3 , the TEDs 452 incorporate slots thatslide into the circuit board 458 to constrain perpendicular movement ofthe TEDs 452 and engage a “bottom” connector to constrain planarmovement while held in the circuit board 458. In this implementation, ateach battery position the circuit board 458 includes two connectors 456which engage a first TED 452 from the “top” and a second TED 452 fromthe “bottom”. Thus, there are corresponding “top” and “bottom”connectors 456 that prevent the TEDs 452 from sliding out of the circuitboard 458. The circuit board 458 includes the control circuitry 459 andholes 422 that may used to affix the circuit board 458 to the batterycarrier, thus bringing the TEDs 452 in contact with the batteries. Inthis implementation, the control circuitry 459 has the additionalability to independently control the temperature of each battery, as asingle circuit board may have two individually controllable TEDs 452 ateach battery location.

FIG. 5A represents one implementation of a radiator 520 showing acut-away of the interior. The radiator 520 may have a “plate and fin”design as represented in the figure where there are fins 521 positionedwithin the interior between the two outer plates 524. Preferably, thefluid passages in the plates 524 are sized and configured so that fluidflow is substantially equalized through the fins 521. As represented inthe figure, on the fluid inlet side the upper longitudinal portion ofthe plate starts at a larger diameter than where it ends, while thelower longitudinal fluid plate diameter is larger near the fluid exit.In this way larger inlet diameters to the fins are paired with smallerexit diameters from the fins so fluid flow is equalized through themultiple sets of the fins 521.

Heat is removed from the radiator 520 by a heat transfer fluid (notshown) flowing through the radiator 520. The heat transfer fluidincludes fluids that transfer heat primarily through a phase change.

The radiator 520 may include attachment spacers 523 that contact thebattery carrier and that include holes 522 that may be used to affix theradiator 520 to the TEDs, and then to the battery carrier. The spacers523 provide a solid surface for the holes 522 and assist in preventingthe fins 521 from being damaged when the radiator 520 is tightlyaffixed.

The fins 521 are preferably positioned where the TEDs are located in thecircuit board to enhance cooling within the radiator 520 at theselocations and to assist in providing structural integrity to theradiator 520 when the radiator is tightly affixed. While a specificplate and fin implementation is represented in the figure, otherimplementations may be used that provide the desired contact with theTEDs.

FIG. 5B provides a representation of a compression plate 580 includingholes 523. The compression plate 580 may be placed on the outside faceof the radiator 520 to provide a clamping force that holds the radiator520 to the TEDs of the circuit board and then the TEDs to the batteries.Studs (not shown) may be provided in the battery carrier that extendsthrough the holes in the circuit board, the holes 522 in the radiator520, and through the holes 523 in the compression plate 580. Nuts (notshown) may then be threaded onto the studs to apply compression force tothe compression plate 580, thus applying relatively even compressionforce to hold the radiator and the circuit board to the batteries andthe battery carrier. Alternatively, bolts (not shown) may be passedthrough the holes 523 that thread into threaded inserts (not shown) inthe battery carrier to provide a similar compression force to thecompression plate 580. Alternatively, if the battery carrier lacksthermal spacers between the batteries, thus placing the battery cases incontact, the sides of the battery cases may be equipped with studs forattachment of the compression plate 580.

To provide a clear and more consistent understanding of thespecification and claims of this application, the following definitionsare provided.

Conduction is the transfer of heat through contact with a solid.

Convection is the transfer of heat through the movement of a contactedfluid.

Thermoelectric devices (TEDs) are solid-state devices that provide acold side and a hot side in response to an electrical input. Thus, whenan electric potential is applied to a thermoelectric device, the devicemoves heat from the cold side of the device to the hot side of thedevice. Reversing the applied potential results in heat travelingthrough the device in the opposite direction, thus reversing the hot andcold sides of the device. Devices of this type are often referred to asPeltier coolers.

Surrounding air in most instances will be the ambient atmosphere able toconvectively absorb heat from a heated surface contacting the air.However, it is possible to replace the surrounding air with a deviceand/or fluids other than air that continue to move the heat for finaltransfer to the air, earth, and the like.

Note that spatially relative terms, such as “up,” “down,” “right,”“left,” “beneath,” “below,” “lower,” “above,” “upper”, “top”, “bottom”,and the like, may be used for ease of description to describe oneelement or feature's relationship to another element(s) or feature(s) asillustrated in the figures. Spatially relative terms are intended toencompass different orientations of the device in use or operation inaddition to the orientation depicted in the figures. For example, if thedevice in the figures is turned over or rotated, elements described as“below”, or “beneath” other elements or features would then be oriented“above” the other elements or features. Thus, the exemplary term “below”can encompass both an orientation of above and below in relation toanother element or feature. The device may be otherwise oriented(rotated 90 degrees or at other orientations) and the spatially relativedescriptors used herein interpreted accordingly.

The simplified diagrams and drawings do not illustrate all the variousconnections and assemblies of the various components, however, thoseskilled in the art will understand how to implement such connections andassemblies, based on the illustrated components, figures, anddescriptions provided herein, using sound engineering judgment.

While various aspects of the invention are described, it will beapparent to those of ordinary skill in the art that other embodimentsand implementations are possible within the scope of the invention.Accordingly, the invention is not to be restricted except in light ofthe attached claims and their equivalents.

1. A temperature-controlled power system, the temperature-controlledpower system comprising: batteries; and a thermal transfer system, wherethe thermal transfer system comprises: at least one circuit board;control circuitry in electrical or wireless communication with the atleast one circuit board; at least two active thermoelectric devices heldby the at least one circuit board, where each of the at least two activethermoelectric devices contacts and is in thermal communication with adifferent battery; the at least one circuit board comprising cut-outs toreceive and hold the at least two active thermoelectric devices; and atleast one radiator in conductive heat transfer with the at least twoactive thermoelectric devices.
 2. The power system of claim 1, furthercomprising a battery carrier that carries the batteries.
 3. The powersystem of claim 2, the battery carrier comprising a base on which thebatteries reside.
 4. The power system of claim 3, the battery carrierfurther comprising one or more divider between the batteries andopposing ends of the batteries.
 5. The power system of claim 2, wherethe battery carrier comprises a thermally insulative material.
 6. Thepower system of claim 2, where the battery carrier further comprisesmounting points chosen from studs and threaded inserts.
 7. The powersystem of claim 2, where the batteries comprise cases having studsconfigured to attach a compression plate.
 8. The power system of claim2, the at least one radiator comprising fins contacting the at least twoactive thermoelectric devices and attachment spacers contacting thebattery carrier.
 9. The power system of claim 1, the at least two activethermoelectric devices comprising opposing longitudinal slots onopposing longitudinal sides configured to mechanically engage thecut-outs of the at least one circuit board.
 10. The power system ofclaim 1, the at least two active thermoelectric devices comprisingcontacts that mechanically engage and establish electrical communicationwith connectors of the at least one circuit board.
 11. The power systemof claim 10, the connectors configured to prevent the at least twoactive thermoelectric devices from moving up and down freely in theplane of the at least one circuit board.
 12. The power system of claim1, the at least two active thermoelectric devices comprising slots onopposing sides and contacts on a bottom side to mechanically engage thecut-outs on opposing sides and the connectors of the at least onecircuit board.
 13. The power system of claim 1, the at least one circuitboard configured to allow the at least two active thermoelectric devicesto slide into the at least one circuit board and be movement constrainedin dimensions perpendicular to the at least one circuit board.
 14. Thepower system of claim 1, where the at least two active thermoelectricdevices are sized to correspond to a width and height of exposed sidesof the batteries.
 15. The power system of claim 1, where at least 30% ofthe area of at least one side of each of the batteries contacts and isin thermal communication with the at least two active thermoelectricdevices.
 16. The power system of claim 1, where each of the batteriescontacts a pair of the at least two active thermoelectric devices onopposing sides.
 17. The power system of claim 1, where the batterieshave opposing sides, each opposing side in contact with at least one ofthe at least two active thermoelectric devices.
 18. The power system ofclaim 1, where a side of one of the batteries contacts at least two ofthe active thermoelectric devices.
 19. The power system of claim 1, thecontrol circuitry configured to monitor temperature sensors inside thebatteries, outside the batteries, or both inside and outside thebatteries.
 20. The power system of claim 1, the control circuitryconfigured to adjust a voltage applied to the at least two activethermoelectric devices.
 21. The power system of claim 1, the controlcircuitry configured to adjust a voltage flowing from or into thebatteries.
 22. The power system of claim 1, the control circuitryconfigured to estimate a temperature of the batteries in response to avoltage obtained from the at least two active thermoelectric devices.23. The power system of claim 1, the control circuitry configured tomonitor and control the temperature of the batteries individually. 24.The power system of claim 23, the control circuitry configured to heat afirst battery and cool a second battery of the batteries.
 25. The powersystem of claim 1, the at least one radiator comprising a heat transferfluid.
 26. The power system of claim 25, the control circuitryconfigured to alter a flow rate of the heat transfer fluid through theat least one radiator.
 27. The power system of claim 1, the at least oneradiator comprising a solid heat sink lacking a heat transfer fluid. 28.The power system of claim 25, the at least one radiator comprising aplate and fin design.
 29. The power system of claim 28, where the platesare configured to match larger diameter fin entrances with smallerdiameter fin exits and to match smaller diameter fin entrances withlarger diameter fin exits.
 30. The power system of claim 1, furthercomprising a compression plate configured to apply a clamping forceagainst the at least one radiator.
 31. The power system of claim 1,where the at least two active thermoelectric devices comprise at leastfour active thermoelectric devices, the at least one circuit boardcomprises at least two circuit boards, where each of the at least twocircuit boards hold at least two of the at least four activethermoelectric devices, and the at least one radiator comprises at leasttwo radiators, where each of the at least two radiators contacts atleast two of the at least four active thermoelectric devices.
 32. Thepower system of claim 1, where the batteries each comprise: a casecomprising a can attached to a lid, where the case comprises a sealbetween the can and the lid; a cell having first and second electrodesexposed from an exterior layer of polymeric material of the cell, the atleast two electrodes comprising an anode electrode and a cathodeelectrode, where the case encloses the cell; at least two posts exposedfrom the case; at least two contacts enclosed by the case, where a firstof the at least two posts is in electrical communication with a first ofthe at least two contacts and a second of the at least two posts is inelectrical communication with a second of the at least two contacts; andat least a first heat transfer bar in electrical and thermalcommunication with the first electrode and the first of the at least twocontacts, where the first heat transfer bar mechanically holds the firstelectrode, the first heat transfer bar comprises a first side that isthermally and electrically conductive and a second side that isthermally but not electrically conductive, and where the second side ofthe first heat transfer bar contacts at least one inner side of the canand the can provides the primary path for heat transfer from the cell.33. A method of transferring heat from a battery cell to surroundingair, the method comprising: generating heat from the interior layers ofa cell by flowing current into or out of the cell; conductivelytransferring the heat from cathode and anode layers of the interiorlayers of the cell to an exterior cathode electrode of the cell and toan exterior anode electrode of the cell, respectively; conductivelytransferring the heat from at least one of the electrodes to a heattransfer bar contacting the at least one of the electrodes; conductivelytransferring the heat from the heat transfer bar through a thermallyconductive and electrically insulative material into an interfacing faceof the heat transfer bar; conductively transferring the heat from theinterfacing face into a can of the battery, where the can in combinationwith a lid forms a case that encloses the battery cell, and where theinterfacing face provides the primary path for heat transfer from thebattery cell; conductively transferring the heat from the can of thebattery to a cold side of an active thermoelectric device, where theactive thermoelectric device transfers the heat from the cold side to ahot side; conductively transferring the heat from the hot side of thethermoelectric device to a radiator, where the radiator convectivelytransfers the heat to surrounding air.
 34. The method of claim 33,further comprising where the radiator conductively transfers the heat toa heat transfer fluid and the heat transfer fluid convectively transfersthe heat to the surrounding air after the heat transfer fluid leaves theradiator.
 35. The method of claim 33, where electricity flows betweenthe electrodes and an electrically and thermally conductive side of theheat transfer bars, contacts, and posts.
 36. The method of claim 34,where in response to a potential measured across the activethermoelectric device, control circuitry regulates the flow of the heattransfer fluid.
 37. The method of claim 34, where in response to atemperature reading from a temperature sensor, control circuitryregulates the flow of the heat transfer fluid.